code: def _download(path: str, url: str):
      """
      Gets a file from cache or downloads it
  
      Args:
          path: path to the file in cache
          url: url to the file
      Returns:
          path: path to the file in cache
      """
      if url is None:
          return None
  
      if (
          not torch.distributed.is_initialized()
          or torch.distributed.get_rank() == 0
      ) and not os.path.exists(path):
          os.makedirs(MEGATRON_CACHE, exist_ok=True)
          logging.info(f"Downloading from {url} to {path}")
          downloaded_path = wget.download(url)
          shutil.move(downloaded_path, path)
      # wait until the master process downloads the file and writes it to the cache dir
      if torch.distributed.is_initialized():
          torch.distributed.barrier()
  
      return path
  
file_path: NeMo/nemo/collections/nlp/modules/common/megatron/megatron_utils.py
imports: import os
  import shutil
  from typing import Dict, List
  import torch
  import wget
  from torch.hub import _get_torch_home
  from nemo.utils import logging
label_desc: Use image node_id 9 for calling a global function with example usage: _download(path, url) and returns: path, None